PRESENT SIMPLE:
a. for permanent situations Ex: Every Wednesday I have English lab
PAST SIMPLE:
a. a completed action in the past Ex: Last month I went to Switzerland.
PAST PROGRESSIVE:
A. an action in progress at a certain time in the past Ex:The teachers were taking lessons all weeks
Edit by Jorge Suntaxi

PAST PROGRESSIVE rule#3
Past habits or repeated actions in the past (often used adverbs of frecuency)
the f1 didn't always were with technologically advanced, I think it were cheaper
Edited by Luis Espinosa
PAST PROGRESSIVE rule·#2
The assitant was making fotocopies while was counting me my money to paid it.
by Pablo Cabrera

PAST SIMPLE rule#3:
Past habits or repeted actions en the past.
Kick Boxing became my favorite sport.
Edited by Vinicio Rosas.

PAST PROGRESSIVE
RULER 2 : We used the past progressive with actions that were happening at the same time in the past
EXAMPLE: students were studing while their parents were working
-----------EDITED BY CARLOS SANCHEZ----------

PRESENT SIMPLE RULE "C"
for general truths
example: "People eats every day"
edited by Rolando Quingatuña

PAST PROGRESIVE RULE "2"
Actions that were happening at the same time in the past
example: people were traveling in car around the city while other were walking
edited by Rolando Quingatuña

PAST SIMPLE rule#1:

A COMPLETE ACTIONS IN THE PAST.
I bought a car the last week
EDITED BY ROBERTO SALAZAR